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    A new soluble Schiff base polymer with a double azomethine group synthesized by oxidative polycondensation
    (TAYLOR & FRANCIS LTD, 2006) Oezbuelbuel, A.; Mart, H.; Tuncel, M.; Serin, S.
    A Schiff base monomer was synthesized by the condensation reaction between salicylaldehyde and ethylenediamine. The Schiff base polymer, with a double azomethine group, was prepared by oxidative polycondensation (OP) reaction of monomer in aqueous alkaline medium with NaOCl as an oxidant at 90 degrees C. The monomer and polymer were characterized by UV-Vis, FT-IR, H-1-and C-13-NMR spectroscopic studies, which revealed that the polymer synthesized by OP is composed of oxyphenylene (55%) and phenylene (45%) units. The polymer was soluble in aqueous alkaline, THF, DMF and DMSO. The thermal properties of monomer and polymer were evaluated by differential thermal analysis (DTA) and thermogravimetric (TG) analyses. According to TG, the 5% and 50% weight loss temperatures of the polymer were 200 degrees C and 800 degrees C, respectively.
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    Investigation of Effects of Some Schiff Bases on Behaviour of Mild Steel in Acidic Medium
    (ASIAN JOURNAL OF CHEMISTRY, 2014) Kahyaoglu, H.; Tuncel, M.
    This study investigated the effects on the behaviour of mild steel in 0.1 M HCl and 0.1M H2SO4 solution of the [4-(3-methoxy-salicylideneamino)-5-hydroxynaphthalene-2,7-,disulfonic acid diisodium salt (L-1) and 4-(3-methoxysalicyaldimino)-5-hydroxy-6-(2-nitrophenylazo)-2,7-naphthalene disulfonic acid disodium salt (L-2) in different concentrations with current-potential and electrochemical impedance spectroscopy (EIS) techniques. Polarization curves revealed that Schiff bases are mixed type inhibitors. Adsorption of Schiff bases on mild steel surface is spontaneous and,obeys Langmuir's isotherm. As a result, the inhibition efficiency of L-2 is higher than L-1 for the studied medium. Moreover, inhibition efficiency increases with increase in the concentration of the inhibitor.
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    Synthesis and characterization of thermally stable Schiff base polymers and their copper(II), cobalt(II) and nickel(II) complexes
    (ELSEVIER SCIENCE BV, 2008) Tuncel, M.; Ozbulbul, A.; Serin, S.
    In this study, the Schiff base monomers [(M-1; N'-p-phenylenebis(salicylideneimine)) and ethylenediamine (M-2; N, N'-p-ethylenebis(salicylideneimine))] were synthesized by the condensation reaction between p-phenylenediamine and aromatic aldehydes. The Schiff base polymers (SBPs) having double azomethine groups were prepared by oxidative polycondensation (OP) reaction of monomers in aqueous alkaline medium with NaOCI [P-1; poly-(N,N'-p-phenylenebis (salicylideneimine)) and P-2; poly-(N,N'p-ethylenebis(salicylideneimine))] as the oxidant at 90 degrees C. Average molecular weights of SBP were determined by get permeation chromatography (GPC). Metal complexes of the SBP were synthesized by the reaction of polymers and metal salts. The monomers and SBP were characterized by elemental analyses, GPC, thermogravimetric analyses, UV-Vis, FT-IR, H-1 and C-13 NMR spectroscopic studies. Also the new Cu(II), Ni(II) and Co(II) complexes of SBP were prepared and characterized by elemental analyses, UV-Vis, FT-IR, atomic absorption spectroscopy (AAS), thermogravimetric analyses and magnetic susceptibility measurements. The results suggested that the SBP and metal ions in 1:1 molar ratio produced binuclear complexes with oxygen and nitrogen donor atoms. All synthesized complexes have dimeric structures by the polymeric ligand units. The weight losses of P-1-CU, P-2-Ni and P-1-Co complexes were found as 57%, 60% and 61%, at 900 degrees C, respectively. Thermal stability of P-1 complexes is higher than that of P-2 complexes. Magnetic moment studies showed that all complexes have various configurations. The metal ion uptake studies were done by batch technique. The polymer P-1 was determined to be more effective in removing Cu(II) ions than the P-2 polymer in batch technique. (c) 2007 Elsevier Ltd. All rights reserved.